Inline piston check valves ensure media travels through a system in the intended direction and prevent backflow. Inline valves create a linear flow path for media to minimize pressure drops and ensure efficient flow. Incoming media increases pressure on the inlet side to open the valve by moving the piston away from the seat. When pressure on the inlet side of the valve is lower than the outlet (back-siphonage), the piston drops into the valve seat to stop the backward flow of media and contaminants. These valves are suitable for low-flow applications and low-viscosity media in various industrial, manufacturing, and treatment operations.